Azo dyestuffs



any diazo compound or diazo azocompound with Patented May 7, 1940' I I,UNITEDT STATES PATENT OFFICE AZO DYESTUFFS Hans Roos 'Leverkusen-I. G.Werk, Germany,

assignor to General Aniline & Film Corporation, a corporation ofDelaware 4 Claims. (Cl. 260-187) to a pure white both in a neutral aswell as in an alkaline reacting medium.

The dyestuff obtainedin this manner corre- The present inventionrelatesito new az o dyestuffs, more particularly it relates to azodyestuffs which may be represented by the general formula sponds to. thefollowing formula: 5 H OH 4 1 I HOaS\ c oon R-N=N H- OQ I I QN= I I noasc N DEN-R 1 H (J D wherein R stands for the radical of a diazo com-'pound suitable for preparing azo dyestuffs with the inclusion of adiazoazo-compound,'R' stands for a radical of the benzene series, and R."stands for a radical. of a nondiazotizable yellowcomponent of the groupconsistingof 1-'aryl-5-pyraz clone-B-carboxylic acids and ortho-hydroxycarboxylic acids of the benzene series.

My new dyestuffs are obtainable by coupling Ewamp le 2.10.7 parts byweight of ortho-tolcoupled with a solution alkaline to sodium carbonateof 36.5 parts by weight of2-para-aminobenzoylamino-5-naphthol-7-su1fonic acid. For the rest thereis proceeded as indicated in Example 1, and a dyestuif dyeing somewhatmore'reddish shades than the dyestuff of Example 1, but. exertingotherwise similar propertiesis obtained, which can be discharged to apure White both in a neutral as well as in an alkaline reacting medium.

' The dyestufi obtained in this manner corresponds to the followingformula:

a 2-aminobenzoylamino 5-naphthol-7sulfonic acid, further diazotizing andcoupling with a l-ary1-5-pyrazolone-3-carboxylic acid or anortho-hydroxy carboxylic acid of the benzene series,

25 which yellow components may bear in the aryl 9 nucleussubstituenta'such'as halogen, alkyl, the H033 carboxylic acid group, thesulfonic acid group, C

there'being excluded, however, the amino group. l 1

My new "dyestuffs are, in form of their alkali Q (JO-NO metal salts,generally red to brown powders, dye- OH ing the vegetable fibergenerally bluish red to brown shades, which can be discharged to a pureWhite both in a neutral as well as in an alkaline reactin medium.

The invention is illustrated by the following examples, without,however, being restricted thereto:

Example 1.-9.3 parts by Weight of aniline are diazotized in the knownmanner and coupled 40 with a solution alkaline to sodium carbonate of36.5 parts by weight of 2-meta-amino-benzoylamino--naphthol-7-sulfonicacid. The dyestuff formed is filtered off with suction, stirred into apaste as finely as possible, and diazotized, at room temperature, bystirring for an hour with nitrite and hydrochloric acid. Then thediazotization mixture is stirred into a solution alkaline to sodiumcarbonate of 20.5 parts by weight of 1- Emample 3. 27.? parts by Weightof 4'-aminoazobenzene--sulfonic acid' are diazotized and coupled, in asolution acid to acetic acid, in the known manner, with 36.5 parts byweight of 2- para-aminobenzoylamino-5-naphthol-7 sulfonic acid. Bysuspending with water, the dyestuff purified by previous isolation isfinelydispersed and diazotized with an excess of nitrite andhydrochloric acid; Then it is coupled, in a solution alkaline to sodiumcarbonate, with 22 parts by weight of 1-phenyl-5-pyrazolone-3-carboxylicacid. The dyestuff obtained dyes the vegetable fiber bluish red shades,which are dischargeable to a pure white both in a neutral as well as inan alkaline reacting medium.

The dyestufi obtainedin this manner corresponds to the followingformula:

coon v 1 .Y a I; I NH QO O -N= NC/H 6041-6 HQ,SON=NON=N 55 Whensubstituting the aminoazobenzene mono-v sulfonic acid by an equivalentquantity of the amino azo dyestuff from diazotized2-naphthylamine-4:,8-disulfonic acid and meta-toluidine andphenyl-5-pyrazolone-3-carboxylic a c i d. T h e coupling is sooncomplete, and the dyestufi is isolated in the known manner. It dyescotton 60 very clear orange shades, which can be discharged uidine arediazotized-in the known manner and working otherwise according to thedirections given in paragraph 1 of the example, there is obtained adyestufi yielding somewhat more bluish shades, which also can bedischarged to a pure white both in a neutral as well as in an alkalinereacting medium,

Example 4.13.6 parts by weight of diazotized monoformyl-metaphenylenediamine are coupled, as indicated in Example 1, with 36.5 parts byweight of 2-para-aminobenzoylamino-5-naphthol-l-sulfonic acid andfinally, likewise as indicated in Example 1, with 20.5 parts by weightof the methyl ester of lphenyl-5-pyrazolone-3-carboxylic acid. Afterhaving been isolated, the dyestuff is boiled for hour in a suspension ofsulfuric acid of 5% strength. Thus a dyestufi is obtained which dyescotton scarlet red shades and which can be developed on the fiber in theknown manner with beta-naphthol to a well dischargeable scarlet which isfast to washing. By developing with diazotized bases, such as forinstance para-nitraniline and similar ones, reddish brown shades areobtained, which can be discharged to a pure white both in a neutral aswell as in an alkaline reacting medium.

The dyestufi obtained in this manner corresponds to the followingformula:

is isolated in the known manner; it dyes cotton a yellowish red of gooddischargeability both .in a neutral as well as in an alkaline reactingmedium.

When using in this example ortho-toluidine, ortho-anisidine or otherbases of this kind, more bluish red dyestuffs of similar properties areobtained.

Example 6.-13.6 parts by weight of meta-aminoformanilide are diazotizedin the usual manner with nitrite and hydrochloric acid. For the restthere is proceeded exactly as indicated in Example 5, using, however,for the final coupling 15.5 parts byweight of ortho-cresotinic acid;-

After isolation the dyestufi is suspended in sulfuric acid of 5%strength and heated at boiling temperature for about hour. The dyestufiob tained in this manner, of the formula N=N coon l NHOO MQOH HOsS OHcan be diazotized and developed on the fiber in the known manner withdiazotized paranitraniline. In the latter case a brown of gooddischargeability both in a neutral as well as in an alkaline reactingmedium is obtained.

I claim:

1. Dyestuffs of the general formula wherein R stands for a memberselected from the group consisting of radicals of the benzene series andnaphthalene series and monoazocompounds thereof, R stands for a benzenenucleus and R. stands for the radical of an orthohydroxy-benzenevcarboxylic acid, dyeing the vegetable fiber generallybluish red tobrown shades, which can be discharged to a pure white 7 both in aneutral and in an alkaline reacting medium.

2. Dyestuffs of the general formula wherein R and R. stand for benzenenuclei and R stands for the radical of an orthorhydroxy- ,benzenecarboxylic acid, dyeing the vegetable fiber generally bluish red tobrown shades, which i can be discharged to a pure white both in aneutral and in an alkaline reacting medium. a 3. The dyestufi having inits free state the 'following formula HOaS dyeing the vegetable fiberyellowish red shades,

of good dischargeability both in a neutral and in an alkaline reactingmedium.

4. The dyestufi having in its free state the following formula yieldinwhen developed on the fiber with diazo- .tized para-nitraniline brownshades of good dis-v chargeability both in a neutral and in an alkalinereacting medium.

, HANS ROOS.

